Velocity/altitude sensing automatic parachute release



O United States Patent [111 3,547,383

[72] inventor Willard D.Carpeuter,.lr. 2,812,148 11/1957 Fogalet al. 244/150 New York, N.Y. (6669 Oakridge Road, Sun 3.] 12,091 1 1/1963 Snyder 2441150 I N ga g s Primary Examiner-MiltonBuchler [2]] Assistant Examiner-James E. Pittenger [22] 1968 Attorney-Matthew M. Russo [45] Patented Dec. 15,1970

ABSTRACT: A parachute release device having an altitude [54] alum/ALTITUDE SENSmG AUTOMATIC sensing mechanism for initially setting and arminga decision making means at a preset first altitude. Said sensing PARACHUTE RELEASE 15 cm 7 Dnwh' Fm mechanism thereafter providing a second signal to said decls|on means at a second preset altitude. A parachute release n 4/150 apparatus operably connected to receive an activating input n 17/56 from said decision means only when the time differential Search between initial and said second signal is less than a 142 selected time interval. whereby, said release apparatus will only deploy said parachute if the rate of descent is.indicative [56] Ream cm of a malfunction or failure of the main parachute to deploy.

UNrrED STATES PATENTS Additionally, there is provided means for calibrating and ad- 2,175,634 10/1939 McQuillen 244/ 150 justing said sensing mechanism and an indication of any in- 2,505,869 5/1950 Quilter 244/150 operativeness on the part of the entire device.

ME MAN/.5 M

VELOCITY/ALTITUDE SENSING AUTOMATIC PARACIIUTE RELEASE BACKGROUND OF THE INVENTION l Field of the Invention The present invention generally relates to improvements in parachute deployment, and more particularly pertains to new and improved automatic parachute deployment, wherein, the parachute is activated and opened by a device which senses two successive barometric pressures and the time period therebetween. These parameters must occur in a selected order and within a preselected period.

2. Description of the Prior Art n In the field of automatic parachute openers it has been the general practice to employ release mechanisms which must be armed for activation just prior to the chutists leaving the aircraft and must thereafter be manually disarmed when the necessity therefor no longer exists. These devices are commonly operated upon the principle of relative barometric pressure and are usually, though not necessarily, applied to a secondary or reserve parachute. In operation, as for example, a sport parachutist will equip himself with a main and a reserve parachute. Upon jumping he will arm or activate the automatic ripcord release mechanism of his reserve parachute so that in the event his manually operated main chute fails to deploy for any reason, his reserve parachute will be released automatically when he descends to a preselected altitude. Thus, if the chutist himself is unable to make the decision relating to the release of the reserve parachute, it will be discharged automatically. This safety apparatus at first observation appears to satisfy all the requirements for providing a foolproof backup system. There are, however, several critical drawbacks which become readily apparent upon closer analysis. First, the parachutist must manually arm the release mechanism before jumping. He must thereafter deploy his main chute and should he fail to do so or should the chute malfunction his reserve-chute will be activated at the preset altitude. However, it should be borne in mind that if his main chute is operative he must manually disarm the automatic release mechanism. Otherwise it will of its own operation deploy his reserve chute and he will descent hazardously under two canopies. In other words, the chutist must rememberto disarm the reserve chute. Certain conditions, such as physical inability, forgetfulness due to panic or stress, might endanger the safety of the parachutist bythe initial use of a safety or reserve chute. Essentially, the requirement of two positive actions on the part of the user has been obviated by the present invention in that the rate or velocity of descent is employed to automatically deploy the reserve chute without the intersecession of the user.

SUMMARY OF THE INVENTION The general purpose of this invention is to provide an automatic ripcord release device that has all the advantages of similarly employed prior art devices and has none of the above-mentioned inherent disadvantages. To attain this, the present invention provides a unique arrangement of a pressure/altitude sensing means for developing a pair of outputs, one each at two preselected altitudes. A timing/decision electronic means stores the first signal and if the second signal arrives before a specified time interval, fires the ripcord and deploys the reserve parachute. In the'alternative, if the time period is exceeded, then the device is automatically inactivated. Thus, the decision to deploy is directly dependent on the chutists rate of descent (pressure/altitude vs. time).

An object of the present invention is to provide a fully automatic parachute opening device whose activation is directly dependent on the rate of descent of the user.

Another object is to provide a simple, inexpensive, reliable ,and adjustable electronically controlled parachute deploying device.

Still another object is to provide a parachute opening device which is self-arming and which need not be subsequently disarmed by the user and which is adapted for use with presently commercially available ripcords.

Other objects and many of the attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, in which like reference numerals designate like parts throughout the figures thereof and wherein:

FIG. I is a block diagram of the basic functional means embodying the principle of the present invention;

FIG. 2 is a circuit diagram of a preferred embodiment made in accordance with the principles of this invention;

FIG. 3 is a circuit diagram of another embodiment made in accordance with the principles of this invention employing operational means different from those of FIG. 2;

FIG. 4 is a perspective view of a ripcord release mechanism employing the solenoid of FIG. 3;

FIG. 5 (A 8: B) is a pictorial representation of the sequence of operations wherein the device of this invention is employed; and

FIG. 6 is a relatively simple embodiment made in accordance with the principles of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT different barometric pressures and provides an output for each thereof. Since the device is worn by aparachutist, these barometric pressures correspond to specific altitudes as, therefore, do the two signal outputs. The output signals are applied to a decision making means 11 which senses the sequential order of the altitude signals and the time duration therebetween. If these signals are received'so that the higher altitude preceeds the lower altitude by a period which corresponds to a selected rate of descent based on the difference in altitude, a decision signal will be generated which then activates the ripcord release mechanism 13 to deploy the parachute.

In the illustrated embodiment of FIG. 2, an aneroid bellows I4 is supported (structure not shown) so that its deflecting or expanding portion which carries an operating end-portion I5 is directed upwardly toward metallic contact arm 16 which is pivoted about 17 and is biased downwardly so as to normally remain in contact with stationary contact 18. Supported directly above and in the travel path of the arm 16 are a pair of adjustable contacts 19 and 20. They are supported by any suitable means, such as block 200, and are selectively adjustable toward and away from the arm 16 while being biased downwardly. This permits the contact arm 16 to first abut one of these (lower) and then contact the other simultaneously as the bellows expands. The same result would be attained if the contact arm 16 were flexible, as a spring. A pair of indepen-- Contact arm 16 is electrically connected via its pivot 17 to an electrical energy source such as battery 21, whose opposite end is grounded. As the bellows l4 expands with increased altitude, arm 16 abuts contact 20 and the battery voltage V is applied to tenninal 22 of unijunction transistor 23 through unidirectional diode 24. This voltage also appears across input resistor 25 and effectively terminal 22 is clamped to the battery voltage V. Battery current also flows through resistor 26, causes capacitor 27, to be charged thereby to voltage V.

Further movement of arm 16 under the expanding action of the bellows simultaneously applies the battery voltage V to contact 19 and thus across the voltage divider network comprising series resistors 28 and 29. The voltage at the junction of these two resistors is a function of their respective values and the battery voltage V namely, V.

Thus the capacitor 30 can only attain a voltage less than V while dependent upon the selection of the divider network. The charge rate or time constant is adjusted by variable resistor 31 which forms part of the charging circuit loop. The voltage at capacitor 30 is also connected directly to the emitter terminal 32 of the unijunction transistor 23. Since a unijunction transistor will not conduct unless the emitter voltage exceeds a fraction N (intrinsic stand off ratio) of the voltage between the ohmic contact terminals base-one (B1) 33 and base-two (B2) 22. When Ve (Voltage at emitter) is greater than NV then the resistance between the emitter and B, decreases and current flows from the emitter to B1. This terminal 33 B1 is connected to the gate 3 4 of Silicon Controlled Rectifier 35 and, without a gate potential the SCR will remain nonconducting or in the off state. This SCR 35 is disposed in series with a Squib and this series combination is across or in parallel with capacitor 27. A Squib" is a term applied to an electrically detonated explosive charge. Presently available parachute ripcord handles are provided with such Squibs and when detonated they instantly release the parachute ripcord thus deploying the parachute without any further intervention on the part of the user. The state or condition of the electronic circuitry described thus far is the result of the ascent from ground level to above 1,200 feet AGL of a parachutist having attached to his reserve chute (for automatic deployment) the electronic device of this invention. This is pictorially represented in FIGS. 5 a through d with the chutist jumping somewhat above 1,200 feet AGL and the system armed.

There are presently available unijunction transistors which are programmable. They are also known a as PUT and are three terminal planar passivated PNPN devices. Their basic advantage in addition to simplicity of circuit use, is that they can be used in place of conventional unijunctions but the user can select his resistors to program the characteristics N, R 1,, and lv to meet his particular requirements. The PUT is fully described in the General Electric Electronic Innovations- -Semiconductors published Nov. 1967 and numbered 60.20.

When the chutist descends to 1,200 feet AGL the bellows contracts and the arm 16 is disconnected from terminal 19 thereby removing the battery voltage V from the voltage divider (resistors 28, 29) and from capacitor 30. This capacitor then proceeds to discharge through variable resistor 31 and resistor 29. All other voltages are unaffected since terminal 20 maintains voltage V and also maintains capacitor 27 charged. At sometime thereafter the chutist has descended to 1,000 feet AGL thus causing arm 16 to disconnect from terminal 20 which results in the immediate loss of battery voltage V across capacitor 27. The capacitor has charged to V and this potential is now across the combination of resistor 26 and the resistance between B, (33) and B (22) of the unijunction transistor 23 or R The resistance of shunt resistor 36 which is comparatively negligible and is neglected. The shunt resistor is employed to prevent the leakage current through the unijunction transistor 23 from turning or gating the SCR 35 to its on" state. Thus, the voltage at terminal 0 2) or efi'ectively V5182 becomes (R /R R )Vc 27. If, at this instant, the voltage Vc across capacitor 30 a (at emitter 32) is less than NV then the unijunction transistor 23 will not conduct and SCR 35 will remain oft" With terminal 20 open, capacitor 30 will not continue to discharge through the path consisting of diode 37 and resistor 25 causing the circuit to be effectively disarmed. At the same time capacitor 27 is discharged through resistor 26 and the ohmic contacts of the unijunction transistor. It is quite clear that the decision whether the SCR was gated on denenriflri Pnfirplv on the vnltann qrrncc nununhnr an vi-sink in trolled by variable resistor 31). In other words, by selecting the time constant to be such that the SCR would not fire after a certain elapsed time period from the opening of terminal 19 (1,200 feet AGL) to the opening of terminal 20 (1,000 feet AGL), the unit is disanned. This time period is selected based on the rate of descent of the parachutist such that if his chute opens and is deployed properly be will exceed this period in his descent from 1,200 to 1,000 feet AGL. Since resistor 31 is variable and terminals 19 and 20 can be adjusted for other altitudes, the altitudes employed have been selected merely for illustrative purposes.

Considering now the situation illustrated in FIGS. 5(e2- g2) where the parachutists main chute either fails to operate or is deployed improperly, the system is again in the armed condition when he jumps. Terminal 19 has opened at 1,200 feet AGL and very shortly thereafter terminal 20 opens. Since the time period between these terminal openings is quite small, the voltage Vc30 across timing capacitor 30 has not diminished appreciably due to discharge. At this instant, this voltage Vc30 exceeds Nv and the unijunction transistor conducts turning or gating SCR 35 on since the timing capacitor 30 now discharges through the emitter 32, base-one (B1) and resistor 36 and thereby applies a gate pulse at the gate 34 of the SCR. With SCR 35 now turned on" and presenting a low resistance, capacitor 27 discharges through the Squib, detonating it and releasing the ripcord and deploying the reserve chute.

Diode 38 is effective in electrically isolating the capacitor 27 from the timing circuit comprising resistors 29 and 31 and the capacitor 30. Diode 24 is employed as a safety device. Should the voltage at terminal 20 (1,000 feet) be lost or disabled due to shock, vibration or malfunction prior to opening of terminal 19 (1,200 feet) then, firing would be prevented. It should be noted that the entire electronic operation is dependent on the opening of terminals or the removal of voltage. This form of selective operation or mode permits the most reliable physical operation of the bellows/switch combination.

Consider now the calibration circuitry of FIG. 2. Of paramount concern to a parachutist is altitude, in terms of feet Above Ground Level (AGL), and not altitude based on a device such as an aneroid bellows which is sensitive to atmospheric pressure, a factor, which does not remain constant. It is therefore absolutely necessary to physically position the bellows at a specific point prior to each jump ascent. For this purpose, a stationary contact 18 is supported by member 39 below the arm 16 and electrically connected to lamp 40 which in turn is connected to the collector 41 of transistor 42. The operating end 15 of the bellows is electrically in circuit with a second lamp 43 that has its opposite end tied to the collector 41. The base 44 of the transistor 42 is connected to the anode 45 of Zener diode 46 via base resistor 47 while its cathode 48 is connected to the positive terminal of battery 21. The emitter 49 is connected to one contact 50 of normally open switch 51 while its other contact 52 is applied to the negative terminal of the battery. Calibration is perfonned at Ground Level by first closing switch 51 and observing the condition of lamps 40 and 43. Under the physical conditions illustrated, with the arm 16 abutting contact 18, lamp 40 will be lighted. If it should fail to light then the bellows, which is movable toward or away from the arm 16, must be moved downwardly or away so as to permit arm 16 to rest on contact 18. Lamp 40 lighting circuit path consists of battery positive, arm 16, contact 18, the lamp, collector 41, emitter 49, switch 51 and the battery negative. When the bellows is lowered the lamp 40 will light since Zener 46 is made to conduct and the base resistor 47 voltage at transistor 42 places it in the conducting state thus effectively lowering the resistance between the emitter 49 and the collector 41. Alternately, if lamp 43 fails to light the bellows must be raised until this lamp 43 is lighted. For proper calibration both lamps must be lighted simultaneously. If both lamps fail to light then it is clear that the Zener diode 46 has failed to conduct due to low battery voltage. Thus, failure of.

both lamps to light serves as a direct battery voltage level check.

In the illustrated embodiment of FIG. 3, different elements and components have been employed to perform the operational functions. The battery 60 is across a variable resistor 61 which in conjunction with fixed resistor 62 supplies an adjustable bias voltage to the base 62 of a pressure sensitive transistor 63 whose collector 64 is connected to B+via resistor 65 and whose emitter 66 is grounded. The sensitive or measuring terminal contact 67 is indicated as-shown. When this transistor is mounted with one of faces exposed to some reference pressure e.g. sealed plenum) and the other face exposed to the atmosphere, the voltage at the collector 64 will be proportioned to the atmospheric pressure. Transistors of this variety are commercially available and one such unit is manufactured by Stow Laboratories, Inc. of Stow, Mass. ad and fully described in their publication Pitran-PT-2/PT-3' dated Dec. 1967. The output (collector 64) of the pressure sensitive transistor 63 is applied to the inputs of a pair of identical Schmitt trigger circuits 68 and 69.

A Schmitt trigger is a regenerative bistable circuit whose state depends on the amplitude of the input voltage which is applied through a variable input resistor 70. Assuming that transistor 71 is nonconducting, the base72 of transistor 73 is biased to some voltage by the'voltage divider consisting of resistors 74, 75 and 76. The emitters 77 and 78 of both transistors are at some voltage, slightly less than that of the base bias, due to the forward bias' voltage required by transistor 73. If the input voltage is less than the emitter voltage, transistor 71 is ofi." As the input voltage approaches the emitter voltage, a critical potential is attained where transistor 71 begins to conduct and regeneratively turns off" transistor 73 thus raising the potential at the collector 79 and supplying an output current through the coil 80 of relay 81. With relay 81 energized the normally closed switch 82 is thrown into its open position and voltage from battery 60 removed from upper contact 83. By adjusting the inputresistors or selecting the values of the other components each Schmitt trigger can be made to fire at a selected potential.

Considering a chutist who is above l,200 feet AGL and is descending, the voltage at the Schmitt triggers input will be low and neither relay energized. When he reaches 1,200 feet AGL Schmitt trigger 69 reaches its firing potential and battery voltage is removed from contact 83a. Further descent to 1,000 feet AGL results in Schmitt trigger 68 firing and thereby energizing relay 81 removing battery voltage from contact 83.

Thus it is clear'that the contacts 83 and 83a correspond to contacts 20 and 19 of FIG. 2 which are applied to the decision means which in this case could be identical to that of FIG. 2 and has therefore been deleted.

The release mechanism in this embodiment consists of a solenoid whose winding 90 is connected in series with SCR 91 so that as aforedescribed for FIG. 2, this SCI! 91 will only be fired when the chutist has descended from 1,200 feet AGL to 1,000 feet within a specified time period. This firing of SCR 91 will result in capacitor 92 being discharged through the solenoid and activating the solenoid trip 93 shown in FIG. 4. This result releases the locking mechanism 94 which has been restraining coiled spring 95 and thereupon the spring uncoils and pullsthe ripcord cable to which it is coupled, deploying the reserve chute.

Referring now to !FIG'. 5 and starting .with 54 the chutist 100 at ground level, calibrates his device to the atmospheric level. As the chutist ascends in airplane 101 and attains an altitude of 1,000 feet AGL battery voltage is applied to contact 20 (FIG. 2) thus commencing the charging of capacitor 27 toward its steady state value. When the aircraft has reached 1,200 feet AGL, FIG. 5c battery voltage is applied to contact 19 and timing capacitor 30 starts to c arge toward its steady state resulting in an armed device as at FIG. 5c battery voltage is applied to contact 19 and timing capacitor 30 starts to charge toward its steady state resulting in an armed device as at FIG. 5d where the chutist jumps. I

Two possibilities now exist either as illustrated in FIG. 5e to g, the main chute 102 deploys properly or it malfunctions as in FIGS. 5e2 to 32. Considering case 1, at 1,200 feet AGL battery voltage is removed from contact 19 and timing capacitor 30 starts to discharge. At 1,000 feet AGL battery voltage is removed from contact 20 but since the rate of descent was slow the unijunction 23 did not fire SCR 35 and the Squib was not detonated as explained hereinbefore. Thus, the unit is disarrned and the chutist descends in a nonnal manner. The same result would ensue if the chutist failed to jump and descends in the airplane. I

Under the conditions of case 2 a the main chute either fails 'to open or is deployedimproperly and again at 1,200 feet lAGL the timing capacitor 30 begins to discharge since battery connected with its positive terminal to the pivot 111 of contact arm 112; Two a stationary contacts are provided, a lower altitude contact 113 disposed below thecontact am and an upper altitude contact 114 located above the arm 112. The bellows 115 is supported so as to engage and move the contact arm upwardly with decreasing pressure or increasing altitude. Contact 114 is connected to the filament or heater 116 of an Amperite Time Delay Relay 117 while the lower contact 113 is applied directly to the arm contact 1 l8 of-the normally open relay portion. The stationary contact 119 of the relay 117 is wired to the Squib while the opposite sides of the Squib and the filament are tied to the negative terminal of the battery completing the circuit. The time delay relay operates in a manner such that when the filament is heated, the contact arm is caused to bend (bimetal) and close the circuit. Upon removal of power from the filament the bimetal arm cools and a specific time thereafter opens.

Up to an altitude of 1,000 feet AGL the bellows has been adjusted to allow contact arm 1 12 to rest on terminal 113 thus applying battery voltage at themovable arm 118 of the relay 1 17. At 1,200 feet the arm 112 is open for terminal 113 and in contact with terminal 114 supplying filament power closing the relay but, without battery voltage thereat. When the chutist descends and while the filament is'still hot (although power has been removed therefrom at 1,200 feet AGL) he passes through the 1,000 foot level, 'at which moment, arm 112 again contacts terminal 113 applying battery voltage to relay arm 118. If the chutist reaches the 1,000 foot level before the 'delay relay opens, the Squib will be detonatedLThis, however, is only possible if his rate of descent exceeds that for the case where his main chute has properly deployed. Under such conditions the Squib will release his reserve chute. Under a slow descent the relay will open, before he descends to 1,000 feet AGL and the unit will be disarrned.

Summarizing, the invention provides an automatic parachute ripcord release, especially suited for sport type parachuting. The unit releases the ripcord on the chutists reserve chute at a selectable preset altitude AGL and, this is accomplished only if the chutist is falling at a high rate of descent (i.e. main chute not released or malfunctioned). Essentially, the unit determines the rate of descent and, based on this information, decides whether to detonate a charge (Squib) and release the reserve chute at a preset altitude. Such explosive parachute ripcord handles are presently commercially available. One such handle, found suitable, is manufactured by Steve Snyder Enterprises of Swarthmore, Fa

It should be understood, of course, that the foregoing disclosure relates to only preferred embodiments of the invention and that numerous modifications or alterations may be made therein without departing from the spirit and the scope of the invention as set forth in the appended claims.

I claim:

1. An automatic parachute deployment apparatus 'comprismg:

sensing means for generating a pair of successive electrical output indications, one for each of two selected altitudes;

decision means connected to receive said pair of indications and providing an output therefrom only when the time ina silicon controlled rectifierhaving an anode, a cathode and a gate terminal;

said detonating means connected in series with the free end of said output resistor, said anode and cathode of said terval between said indications is less than a selected SCR and said other terminal of said battery; period, and said indications are received in a particular a firing capacitor connected between said free end of said Sequence; output resistor and said other terminal of said battery;

a parachute ripcord release means connected to be acan electrical connection between said gate terminal and said tivated upon the receipt of said output of said decision one f id i f b contacm means; and 10 8. The apparatus according to claim 7 wherein said detonatwhereby when an upper altitude indication is generated and m means i a "S ib thereafteralower altitude indication, within said selected 9 T apparatus according to claim 8 f th including a period said release means will deploy said parachute. lib ti n circuit comprising: 1

i apparatus according to claim 1 wherein Said sensing a stationary contact supported in abutting relation with said means "fcludes: movable arm when said arm is undefiected;

adlvswble anem'd bellows havmg f movable operatmg a pair of series connected lamps having one end thereof h0g8 length P Proportional to -f electrically connected to said arm and the opposite end a flexible deflecfmg plvmed eiecmcal Contact dlsfposed thereof connected to said operating end of said bellows;

P i S beuws movemem and deflecuon by a calibrating transistor having its collector connected to the contact with said operating end; junction of Said lamps;

" of f dlsposed the oppos'te We of 531d arm a base resistor having one end connected to the base of said from Sam beuows; calibrating transistor;

means supporting said contacts for adjusta movement a Zener diode connected between the other end of said base toward and away,frm and resistor and said one terminal of said battery;

a source of electrical energy connected to said movable a normally open switch having its stationary contacts com whereby f i bellows. acted upon by a nected intermediate the emitter of said calibrating change i preisure cause Sald arm to first transistor and the said other terminal of said battery one of i of contacts and upon a furiher i m whereby said bellows may be correctly adjusted at ground pressure it will also contact the other of said pair 0 conl ev e1 dependent on the ghfi n g ofsaid lamps acts and apply Sald enprgy souice thereto. 10. The apparatus according to claim 1 wherein said sensing 3. The apparatus according to claim 2 wherein said source is means com may a battery having one terminal thereof connected to said arm. p

4. The a aratus accordin to claim 3 wherein said decision a pressure sensitive mnslstqrpavmg i collector an emitter PP 8 a base and a pressure sensitive terminal, means includes: 3 5 a bane afirst electrical unidirectional means; n t

a second electrical unidirectional means; a co .ector tests a third electrical unidirectional means; a series loop electrical path having therein one terminal said a resistor voltage divider network; battery, said collector resistor, said collector, said emitter and the other terminal of said battery;

3 mung capacitor 40 an ad'ustable ari bl r s'st n e on t d b t d a unijunction transistor having a pair of base contacts and J v e e I a c nee e e ween Sal an emitter one terminal of said battery and said base terminal;

a shunt resist'or; a pair of regenerative bistable networks each having an a first loop path having connected in series therein, said one mput and an 9 P termmal and 'f an output of said pair of contac's said first unidirectional means, only when the input thereto exceeds an ad ustable level, Said pair of base contacts said shunt resistor the other each ofsaid inputs electrically connected to said collector terminal of said battery; teltmlnal;

a second loop path having connected in series therein said a of relays each havmg a movable comaef normally one of said pair of contacts, said voltage divider and said connected to a stauolfary i each f Said movable other terminal ofsaid battery; contacts connect to said one terminal of said battery; and

a third series |00p path having included therein Said other f electrical means connecting said output terminal of each of said pair of contacts, said second unidirectional means, blstable P f to "W relay, y the said timing capacitor and said other terminal of said batouputs of said sensmg P Pmvlded at Winona tery; ry contacts of each of saidrelays. p

a variable resistor connected intermediate said divider net apparatus according to cliflm Whel'ein Said work and the junction between said capacitor and said regenemuve blstable networks am Schmm Triggerssecond unidirection means; 12. The apparatus according to claim 11 wherein said electrical means connecting said junction connected to said release means Comprises:

amine"; and a mechanical means for pulling a ripcord having a restrainsaid third unidirectional means electrically connected g P n f r preventing pulling of said ripcor between id other f id i f contacts d one f id a solenoid coupled to said restraining portion for removing ir of ba e o t the same upon activation of the winding of said solenoid;

5. The apparatus according to claim 4 further including: a silcon controlled rectifier having an anode, cathode and a an input resistor electrically connected between said other g terminal, and ng ts ga e C HH CtBd t0 the Output of said pair of contacts and said other terminal of said bat- 0f Said decision tery; and an activating capacitor connected across said battery;

an output resistor having one end thereof connected to the d nding and Said anode and cathode of said SCR conother of said pair of base contacts. nected across said battery.

6. The apparatus according to claim 5 wherein said 13. The apparatus according to claim 12 wherein said unidirectional means are diodes. 7O mechanical means includes a coiled spring and said restraining 7. The apparatus according to claim 6 wherein said ripcord portion is a locking mechanism.

release means includes: 14. An apparatus for automatically deploying a parachute an electrically detonating means having two terminals and having a ripcord handle, comprising:

carried by a ripcord handle of a parachute for releasing an adjustable aneroid bellows having a movable operating end whose length of travel is proportional to pressure;

said parachute;

a flexible deflecting pivoteme ctrical contact ann disposed proximate said bellows for movement and deflection by contact with said operating end;

a first adjustable contact disposed on one side of said arm;

a second adjustable contact disposed on the opposite side of said arm;

a battery having one terminal connected to said arm;

a time delay relay having a filament heater element and a movable heat sensitive switch element normally open to its stationary contact but when heated closing such contact;

an electrically detonable means carried by the ripcord han- 

